Question: If $a + b + c = 1$ and $x + y = 6$, what is $-c - 5x - a - 5y - b$ ?
Explanation: $= -a - b - c - 5x - 5y$ $= (-1) \cdot (a + b + c) + (-5) \cdot (x + y)$ $= (-1) \cdot (1) + (-5) \cdot (6)$ $= -1 - 30$ $= -31$